# Math Help - chain rule?

1. ## chain rule?

Find the derivative of
f(x)=e^4x(x^2+3x)

2. $f(x) = e^{4x}(x^2 + 3x)$

$f'(x) = e^{4x}(2x + 3) + 4e^{4x}(x^2 + 3x)$

$f'(x) = e^{4x}[(2x+3) + 4(x^2 + 3x)]$

I'll leave you to clean up the algebra from here.

3. whoa. how did you do that?

4. product rule + chain rule with the exponential function

5. oh ok. thanks!